It comes just days after the US accused Russia of requesting weapons from the secretive state, following a visit by Moscow's defence minister Sergei Shoigu.

Kim Jong Un inspected munitions factories at the end of last week, watching the production of cruise missiles, aerial vehicles and rocket launchers, news agency KCNA said.

He also stressed the "important responsibilities and tasks in perfecting [the North's] war readiness".

It is believed that Pyongyang is attempting a show of strength in its range of weaponry, while others, including the US, say North Korea is selling arms to Russia.

During his visits, Mr Kim called for the mass production of "various kinds of cutting-edge strategic weapon engines... and thus make a great contribution to bringing about a revolution in developing new strategic weapons of our style", according to the KCNA.

The factory inspections come ahead of US-South Korean military drills later this month, which Mr Kim often views as a practice for invading his country.

The leader held a huge military parade through the North Korean capital last week, where he was joined by Mr Shoigu and an official from China's ruling party, where he displayed new missiles built to hit targets in the US and South Korea.

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Mr Shoigu was given a tour of an arms exhibition, with Mr Kim offering his support for Russia's invasion of Ukraine.

The country has aligned itself with Russia over the war, saying the "hegemonic policy" of the US-led forces in the West meant Moscow had to take action to protect itself.

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Pyongyang denies US insistence that North Korea is supplying weapons to Russia.

Meanwhile, tensions on the Korean peninsula remain high after a number of missile launches from the North, which have included advanced cruise missiles.